Not sure if it's called "curves" in English, but what I am refering to is graphs that repeat over a given time.(adsbygoogle = window.adsbygoogle || []).push({});

ie

f(x) = sin(x)

The problem I am having is understanding the following:

Given:

f(x) = sin(x)

g(x) = cos(x)

Find f(x) - g(x) by A(cos(x - x0)).

Which gives:

A(cos(x - x0)) = A(cos(x0))cos(x) + A(sin(x0))sin(x)

A(cos(x0)) = 1

A(sin(x0)) = -1

thus:

A = sqrt(1^2 + (-1)^2) = 1

Finding x0:

tan wx0 = 1/(-1)

1*x0 = arctan(-1)

x0 = -0.79

Here I'm pretty much lost. I've probably done some mistakes along the way as well :(

What is -0.79? x0 is supposed to be the 'top' of the curve right?

ie to find every top, you would have something like:

x0 +/- |n|*2PI

Where n is a whole number(1..inf) and 2PI would be the period of each "curve".

Could someone explain this to me, I'm trying to learn this by just reading a book and I'm having a hard time.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Harmonic curves

**Physics Forums | Science Articles, Homework Help, Discussion**